PRECUPANU T. Characterizations of hilbertian norms involving the areas of triangles in a smooth space. Stud. Univ. Babeş-Bolyai Math. [Internet]. 2022 Mar. 10 [cited 2025 Mar. 13];67(1):145-9. Available from: https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/1456